This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. As the AIDS pandemic continues to fuel rates of tuberculosis (TB) worldwide, it is important to understand how the human immune system responds to TB in both HIV-positive and HIV-negative settings. This is critical for designing vaccines that protect against TB disease. Intact adaptive immune responses mediated by CD4+ and CD8+ T cells are essential for controlling infection with Mycobacterium tuberculosis (Mtb) but their effector functions, development into memory cells and regulation are poorly characterized. We are characterizing the progression of TB-specific immune responses and their regulation within an individual undergoing antibiotic treatment. We are studying the regulation of Mtb antigen-specific immune responses in HIV negative and HIV positive individuals before and during standard tuberculosis antibiotic therapy. Patient enrollment for these studies is ongoing at Grady Hospital in close partnership between basic science (Rengarajan) and clinical (Ray) investigators. UPDATE: We have recently completed a study focusing on memory responses in latent T infection.